In the past 3 months Groupon has gained more than 15% and Yelp has surged more than 40%. What should you make of the moves?

Jim Cramer is curious, especially since both companies lie at the very heart of new media and the migration from desktop to mobile.

"Most of the Internet companies I follow, indeed most of the technology companies I follow, have been hurt, in some cases almost annihilated, by the migration from the desktop to the handheld," Cramer explained. "Groupon and Yelp, however, have managed to harness mobile, quite well."

The popularity of their mobile apps is partly due to the significant focus both companies put on local commerce - a somewhat underserved niche in Internet.

It seems as people move about town, they like to click on the Groupon app and check their smartphones for coupons. And they like to click on the Yelp! app for restaurant and hotel reviews, as well as insights on nightlife, shopping and more.

Joseph Valenti (L) & Tim Boyle (R) | Bloomberg | Getty Images

Looking at the trend, Cramer sees things he likes.

On the positive side, "Core business metrics, such as more couponing for Groupon, and more reviews for Yelp, are definitely headed in the right direction," he said. It appears both companies have leveraged aggressive growth strategies.

But – considering the gains already -- improved metrics don't necessarily mean their respective stocks have more upside from here.

"Groupon cash flow was negative this quarter," Cramer said. "Although I can see why people might be willing to pay high single digits for the company (as a bet on the promise of new media), I remain somewhat skeptical because, in the end, the bottom line matters most and Groupon still isn't making money."

As for Yelp, Cramer said, "it has become, overnight, one of the most overpriced stocks in the book. Although it could breakout to remarkable profitability rather quickly, I think the nearly $2 billion market cap is already fair value."

All told, Cramer thinks these stocks are worth watching but not buying – at least not at current levels.